Gasification flash steam heat recovery device

Abstract

The utility model relates to the field of novel coal gasification synthesis ammonia, and particularly provides a gasification flash steam heat recovery device which comprises a high-pressure flash tank, the inlet end of the high-pressure flash tank is connected with a black water inlet pipe, one path of the outlet end of the high-pressure flash tank is connected with a saturated hot water tower, and the other path of the outlet end of the high-pressure flash tank is connected with a low-pressure flash tank; the inlet end of the deaerator is further connected with a deaerator water inlet pipe, the outlet end of the deaerator is connected with a saturated hot water tower, the saturated hot water tower is connected with a high-pressure ash water pump, the high-pressure ash water pump is connected with a high-pressure ash water pump water outlet pipe, and the high-pressure ash water pump water outlet pipe is used for delivering gasified water to each water using point for cyclic utilization; and the stripping tower is also connected with a conversion condensate inlet pipe, the outlet end of the stripping tower is connected with a condensate outlet pipe, and the condensate outlet pipe is used for carrying out outward-conveying gasification cyclic utilization. Compared with the prior art, the utility model has the advantages that the energy-saving effect is obvious, environmental protection accidents are avoided, and the environmental protection benefit is obvious.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of novel coal gasification synthetic ammonia, and specifically provides a gasification flash steam heat recovery device. BACKGROUND

[0002] In the gasification process of the novel coal gasification synthetic ammonia, the high-pressure flash steam after the high-pressure flash tank flashing of the black water of the quenching chamber of the gasifier and the black water of the synthesis gas washing tower is about 170 DEG C, and the water vapor content is about 99%, but because the ash-carrying phenomenon is serious, most enterprises adopt the method of first passing through the saturated hot water tower for heat recovery and then sending the acid gas to the flare for combustion treatment, which not only causes the waste of the high-pressure flash steam heat, but also easily causes the flare tail phenomenon due to the high temperature of the high-pressure flash steam, causing environmental accidents.

[0003] At the same time, in the shift process of the novel coal gasification synthetic ammonia process, in order to avoid the influence of ammonia in the shift gas on the low-temperature methanol washing, a shift gas ammonia washing tower is usually designed to wash and remove a small amount of ammonia in the shift gas, the shift condensate at the bottom of the ammonia washing tower has a high ammonia content, in order to realize the further recovery and utilization of the condensate, a stripping tower is usually arranged, the condensate enters the stripping tower, and the ammonia in the condensate is removed by using the stripping process principle and using 0.5 MPa saturated steam.

[0004] In order to effectively solve the above problems, a gasification flash steam heat recovery device is provided, the process of the high-pressure flash steam and the low-pressure flash steam is modified, the heat of the high-pressure flash steam and the low-pressure flash steam is effectively recovered, the flare tail phenomenon is solved, and the amount of 0.5 MPa saturated steam used in the system operation is reduced, thereby saving energy and reducing consumption. SUMMARY

[0005] The utility model provides a gasification flash steam heat recovery device that is reasonable in design, simple in structure, convenient and practical, and energy-saving and consumption-reducing.

[0006] The utility model solves the technical scheme adopted by the technical problems:

[0007] A gasification flash steam heat recovery device, characterized in that it comprises a high-pressure flash tank, a black water inlet pipe is connected to the inlet end of the high-pressure flash tank, a saturated hot water tower is connected to one outlet end of the high-pressure flash tank, and a low-pressure flash tank is connected to the other outlet end of the high-pressure flash tank.

[0008] The low-pressure flash tank is connected with a deaerator in one way and a stripping tower in another way, the deaerator is further connected with a deaerator water inlet pipe at an inlet end and connected with the saturated hot water tower at an outlet end, the saturated hot water tower is connected with a high-pressure grey water pump, the high-pressure grey water pump is connected with a high-pressure grey water pump water outlet pipe, and the high-pressure grey water pump water outlet pipe is externally sent to each water point for recycling.

[0009] The stripping tower is further connected with a shift condensate inlet pipe, the outlet end of the stripping tower is connected with a condensate outlet pipe, and the condensate outlet pipe is connected with the deaerator water inlet pipe for recycling as make-up water of the deaerator.

[0010] Further, the high-pressure flash tank is connected with the saturated hot water tower through a high-pressure flash steam outlet pipe, connected with the low-pressure flash tank through a black water outlet pipe, connected with the deaerator through a low-pressure flash steam outlet pipe and a deaerator air inlet pipe, and connected with the stripping tower through a low-pressure flash steam outlet pipe and a stripping tower air inlet pipe.

[0011] Further, the inlet end of the stripping tower is further connected with a steam air inlet pipe, and the steam air inlet pipe is further provided with a valve III.

[0012] Further, the stripping tower air inlet pipe is provided with a valve I, and the deaerator air inlet pipe is provided with a valve II.

[0013] Further, the outlet end of the deaerator is connected with a deaerated water pump water inlet pipe, the deaerated water pump water inlet pipe is connected with a deaerated water pump, the deaerated water pump is connected with a deaerated water pump water outlet pipe, and the deaerated water pump water outlet pipe is connected with the saturated hot water tower.

[0014] Further, the outlet end of the saturated hot water tower is further connected with a high-pressure flash steam vent pipe, the high-pressure flash steam vent pipe is sent to a flare for combustion, and the outlet end is connected with the high-pressure grey water pump through a high-pressure grey water pump water inlet pipe.

[0015] Compared with the prior art, the gasification flash steam heat recovery device has the following outstanding advantages:

[0016] The low-pressure flash steam is divided into two ways, one part is sent to the stripping tower, and the other part is sent to the deaerator, compared with the conventional process that the low-pressure flash steam is all sent to the deaerator, the deaerated water temperature of the saturated hot water tower can be reduced by about 30 DEG C, the recovery amount of the high-pressure flash steam heat is increased, the temperature of the high-pressure flash steam vent is reduced, and the flare tailing phenomenon caused by the high temperature of the high-pressure flash steam vent is avoided.

[0017] The steam air inlet pipe is provided with the valve III, in application, the valve I is opened, and the valve III is closed, 0.5MPa steam for the stripping tower is stopped, and steam consumption is effectively saved.

[0018] The utility model discloses not increase new equipment, aiming at the improvement of the existing process, and the investment is small, and the benefit is high. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical scheme in the embodiment of the utility model or prior art, the following will briefly introduce the drawing needed to be used in the embodiment or prior art description, obviously, the drawing in the following description is some embodiments of the utility model, and for those skilled in the art, under the premise of not creating laboriously, other drawings can also be obtained according to these drawings.

[0020] Figure Figure 1 It is a kind of gasification flash steam heat recovery device's structural schematic diagram.

[0021] The marks in the drawing represent respectively:

[0022] 1, high-pressure flash tank, 2, saturated hot water tower, 3, low-pressure flash tank, 4, deaerator, 5, stripping column, 6, high-pressure grey water pump, 7, deaerated water pump, 8, black water inlet pipe, 9, high-pressure flash steam outlet pipe, 10, high-pressure grey water pump inlet pipe, 11, black water outlet pipe, 12, low-pressure flash steam outlet pipe, 13, stripping column inlet pipe, 14, deaerator inlet pipe, 15, deaerated water pump inlet pipe, 16, deaerated water pump outlet pipe, 17, condensate outlet pipe, 18, steam inlet pipe I, 19, shift condensate inlet pipe, 20, valve I, 21, valve II, 22, valve III, 23, deaerator inlet pipe, 24, high-pressure flash steam vent pipe, 25, high-pressure grey water pump outlet pipe. DETAILED DESCRIPTION

[0023] The utility model will be further described in connection with the drawing and specific embodiment, but not as the limitation to the utility model.

[0024] In the utility model, under the condition of not making opposite declaration, the orientation words such as "up, down, left, right" used are usually up, down, left, right shown in the drawing;"inner, outer" refers to the inner, outer relative to the outline of each component itself.

[0025] The following gives a best embodiment:

[0026] As Figure 1 Shown, a kind of gasification flash steam heat recovery device in the embodiment, including high-pressure flash tank 1, the inlet end of high-pressure flash tank 1 is connected with black water inlet pipe 8, one way outlet end is connected with saturated hot water tower 2, and another way is connected with low-pressure flash tank 3;

[0027] The low pressure flash tank 3 is connected with the deaerator 4 and the stripping tower 5, the inlet end of the deaerator 4 is also connected with a deaerator water inlet pipe 23, the outlet end is connected with the saturated hot water tower 2, the saturated hot water tower 2 is connected with the high pressure grey water pump 6, the high pressure grey water pump 6 is connected with a high pressure grey water pump water outlet pipe 25, the high pressure grey water pump water outlet pipe 25 is sent to each water using point for recycling;

[0028] The stripping tower 5 is also connected with a shift condensate inlet pipe 19, the outlet end of the stripping tower 5 is connected with a condensate outlet pipe 17, the condensate outlet pipe 17 is connected with the deaerator water inlet pipe 23, and is recycled as the make-up water of the deaerator 4.

[0029] The high pressure flash tank 1 is connected with the saturated hot water tower 2 through a high pressure flash steam outlet pipe 9, and is connected with the low pressure flash tank 3 through a black water outlet pipe 11, the low pressure flash tank 3 is connected with the deaerator 4 through a low pressure flash steam outlet pipe 12 and a deaerator gas inlet pipe 14, and is connected with the stripping tower 5 through the low pressure flash steam outlet pipe 12 and a stripping tower gas inlet pipe 13.

[0030] The stripping tower 5 is also connected with a steam gas inlet pipe 18, and a valve Ⅲ 22 is arranged on the steam gas inlet pipe 18.

[0031] A valve Ⅰ 20 is arranged on the stripping tower gas inlet pipe 13, and a valve Ⅱ 21 is arranged on the deaerator gas inlet pipe 14.

[0032] The outlet end of the deaerator 4 is connected with a deaerated water pump water inlet pipe 15, the deaerated water pump water inlet pipe 15 is connected with a deaerated water pump 7, the deaerated water pump 7 is connected with a deaerated water pump water outlet pipe 16, and the deaerated water pump water outlet pipe 16 is connected with the saturated hot water tower 2.

[0033] The outlet end of the saturated hot water tower 2 is also connected with a high pressure flash steam vent pipe 24, the high pressure flash steam vent pipe 24 is sent to a flare for combustion, and the outlet end is connected with the high pressure grey water pump 6 through a high pressure grey water pump water inlet pipe 10.

[0034] In the working process of the device, the inlet end of the high pressure flash tank 1 is connected with the black water inlet pipe 8, and the outlet end is connected with the high pressure flash steam outlet pipe 9 and the black water outlet pipe 11. According to the coal consumption of 6.64T / h of the gasification process load, the black water generated by the quenching chamber of the gasifier and the synthesis gas washing tower has a temperature of about 255℃, a pressure of about 6.3MPa, and a flow rate of about 340m3 / h, and is introduced into the high pressure flash tank 1 through the black water inlet pipe 8 for flash evaporation. In the high pressure flash tank 1, a part of the black water is reduced in pressure and becomes high pressure flash steam, the high pressure flash steam has a temperature of 179.9℃, a pressure of 0.9MPa, and a heat of 48804.7KW, and is introduced into the saturated hot water tower 2 through the high pressure flash steam outlet pipe 9 to recover heat. The black water after high pressure flash evaporation has a temperature of 179.9℃, a pressure of 0.9MPa, and a flow rate of about 247.8m3 / h, and is introduced into the low pressure flash tank for further flash evaporation through the black water outlet pipe 11.

[0035] The inlet end of the low-pressure flash tank 3 is connected with the black water outlet pipe 11, and the outlet end is connected with the low-pressure flash steam outlet pipe 12. The black water after high-pressure flashing has a temperature of 179.9℃, a pressure of 0.9MPa, and a flow of about 247.8m3 / h, and is further reduced in the low-pressure flash tank 3, and a part of the black water is flashed into low-pressure flash steam. The low-pressure flash steam has a temperature of 133.5℃, a pressure of 0.2MPa, and a heat of 20933.62KW, and is sent to the deaerator and the stripping column through the low-pressure flash steam outlet pipe 12 to recover heat.

[0036] The inlet end of the deaerator 4 is connected with the deaerator inlet water pipe 23 and the deaerator inlet steam pipe 14, and the outlet end is connected with the deaerated water pump inlet water pipe 15. The low-pressure flash steam with a temperature of 133.5℃ and a pressure of 0.2MPa enters the deaerator through the deaerator inlet steam pipe 14 to provide heat source for deaeration of the deaerator, and the mixed gray water of the gasification process and the high-temperature condensate of the shift process with a temperature of about 70℃ and a flow of 180m3 / h enters the deaerator through the deaerator inlet water pipe 23 to be deaerated and purified. The qualified deaerated water with a temperature of about 120.23℃ enters the deaerated water pump 7 through the deaerated water pump inlet water pipe 15 to be pumped and sent out.

[0037] The inlet end of the saturated hot water tower 2 is connected with the high-pressure flash steam outlet pipe 9 and the deaerated water pump outlet water pipe 16, and the outlet end is connected with the high-pressure gray water pump inlet water pipe 10 and the high-pressure flash steam vent pipe 24. The high-pressure flash steam with a temperature of 179.9℃ enters the saturated hot water tower 2 through the high-pressure flash steam inlet pipe 9, and the deaerated water with a temperature of 120.23℃ enters the saturated hot water tower through the deaerated water pump outlet water pipe 16. The deaerated water with a relatively lower temperature is heated by the high-pressure flash steam, and the temperature is increased to 171℃. The deaerated water is sent to the high-pressure gray water pump through the high-pressure gray water pump inlet water pipe 10 to be pumped and sent out. The high-pressure flash steam is cooled by heat recovery, and the temperature is reduced to below 100℃. The high-pressure flash steam is sent to the flare through the high-pressure flash steam vent pipe 24.

[0038] The inlet end of the stripping column 5 is connected with the stripping column inlet steam pipe 13, the shift condensate inlet pipe 19, and the steam inlet pipe 18, and the outlet end is connected with the condensate outlet pipe 17. A part of the low-pressure flash steam with a temperature of 133.5℃ and a pressure of 0.2MPa enters the stripping column through the stripping column inlet steam pipe 13. The shift condensate with a high ammonia content enters the stripping column through the shift condensate inlet pipe 19. In the stripping column, the shift condensate is stripped by the low-pressure flash steam using the stripping process, and the ammonia in the shift condensate is stripped out. The low-temperature condensate at the bottom of the column is sent to the gasification process for recycling.

[0039] The inlet end of the high-pressure ash water pump 6 is connected with the high-pressure ash water pump inlet pipe 10, and the outlet end is connected with the high-pressure ash water pump outlet pipe 25. The deoxygenated water after absorbing the heat of the high-pressure flash steam enters the high-pressure ash water pump 6 through the high-pressure ash water pump inlet pipe 10 for pressure boosting, and then is sent to each water using point through the high-pressure ash water pump outlet pipe 25 for recycling.

[0040] The inlet end of the deoxygenated water pump 7 is connected with the deoxygenated water pump inlet pipe 15, and the outlet end is connected with the deoxygenated water pump outlet pipe 16. The deoxygenated water after removing the dissolved oxygen in the deaerator 4 enters the deoxygenated water pump 7 through the deoxygenated water pump inlet pipe 15 for pressure boosting, and then is sent to the saturated hot water tower 2 through the deoxygenated water pump outlet pipe 16 to absorb the heat of the high-pressure flash steam.

[0041] Among them, the deaerator inlet pipe 14 is provided with a valve II 21, and the stripping tower inlet pipe is provided with a valve I 20. In normal production, the opening degree of the valve I and the valve II can be adjusted to adjust the gas amount of the low-pressure flash steam entering the deaerator 4 and the stripping tower 5.

[0042] The steam inlet pipe 18 is provided with a valve III 22. When this method is applied, the valve I 20 is opened, and the valve III 22 is closed, and the 0.5 MPa steam for the stripping tower is disabled, thereby effectively saving the steam consumption.

[0043] The low-pressure flash steam is divided into two parts, one part is sent to the stripping tower 5, and the other part is sent to the deaerator 4. Compared with the traditional process in which the low-pressure flash steam is all sent to the deaerator, the temperature of the deoxygenated water entering the saturated hot water tower can be reduced by about 30°C, thereby increasing the amount of recovered heat of the high-pressure flash steam and reducing the temperature of the high-pressure flash steam venting, thereby avoiding the phenomenon of torch tailing caused by the high temperature of the high-pressure flash steam venting.

[0044] The calculation process of the recovered heat is as follows:

[0045] The coal consumption of the gasification process with a load of 6.64 T / h is calculated as follows:

[0046] The deaerator 4 has an inlet water amount of 180 m3 / h and a temperature of 70°C, and the enthalpy value is 2625.3 KJ / kg. The deoxygenation pressure is 0.2 MPa, and under the pressure of 0.2 MPa, the saturated steam temperature of water is 120.23°C, and the enthalpy value is 2706.9 KJ / kg. That is, if the dissolved oxygen in the water entering the deaerator is removed, the water only needs to be heated from 70°C to 120.23°C, and at this time, the low-flash gas heat required to be consumed is Q1=M*(H1-H2)= [180 m3 / h*1000 kg / m3*(2706.9 KJ / kg-2625.3 KJ / kg)] / 3600=4080 KW.

[0047] The total heat of the low-pressure flash steam is 20933.62 KW, and the surplus heat is Q2=20933.62 KW-4080 KW.=16853.62 KW.

[0048] Under this load, the conversion stripping tower normal production needs to consume 0.5MPa steam amount 18T / h, 0.5MPa steam enthalpy is 2748.5 KJ / kg, this part of steam provides the heat for Q3=(18*1000 kg / / h*2748.5 KJ / kg) / 3600=13742.5 KW.

[0049] Because low pressure flash steam surplus heat Q2> conversion stripping tower needed heat Q3, so this method after putting into use, the conversion stripping tower 0.5MPa can be disabled, directly save steam amount 18T / h.

[0050] The above-described embodiments are only one of the preferred specific embodiments of the present application, and the usual changes and replacements made by those skilled in the art within the technical scheme of the present application should be included in the protection scope of the present application.

Claims

1. A gasification flash vapor heat recovery apparatus, characterized by, Including high pressure flash tank, the inlet end is connected with black water inlet pipe, the outlet end is connected with saturated hot water tower in one way, and is connected with low pressure flash tank in another way; The low pressure flash tank is connected with deaerator in one way, and is connected with stripping tower in another way, the inlet end of the deaerator is also connected with deaerator inlet pipe, and the outlet end is connected with the saturated hot water tower, the saturated hot water tower is connected with high pressure grey water pump, the high pressure grey water pump is connected with high pressure grey water pump outlet pipe, and the high pressure grey water pump outlet pipe is sent to each water point for recycling; The stripping tower is also connected with conversion condensate inlet pipe, the outlet end of the stripping tower is connected with condensate outlet pipe, the condensate outlet pipe is connected with deaerator inlet pipe, and is used as the water supplement of the deaerator for recycling.

2. A gasification flash steam heat recovery apparatus according to claim 1, wherein The high pressure flash tank is connected with the saturated hot water tower through high pressure flash steam outlet pipe, and is connected with the low pressure flash tank through black water outlet pipe, the low pressure flash tank is connected with the deaerator through low pressure flash steam outlet pipe and deaerator inlet pipe, and is connected with the stripping tower through low pressure flash steam outlet pipe and stripping tower inlet pipe.

3. A gasification flash steam heat recovery apparatus according to claim 2, wherein, The stripping tower inlet end is also connected with steam inlet pipe, and the steam inlet pipe is also provided with valve III.

4. A gasification flash steam heat recovery apparatus according to claim 3, wherein The stripping tower inlet pipe is provided with valve I, and the deaerator inlet pipe is provided with valve II.

5. A gasification flash steam heat recovery apparatus according to claim 4, wherein The outlet end of the deaerator is connected with deaerated water pump inlet pipe, the deaerated water pump inlet pipe is connected with deaerated water pump, the deaerated water pump is connected with deaerated water pump outlet pipe, and the deaerated water pump outlet pipe is connected with the saturated hot water tower.

6. A gasification flash steam heat recovery apparatus according to claim 5, wherein The outlet end of the saturated hot water tower is also connected with high pressure flash steam vent pipe, the high pressure flash steam vent pipe is sent to torch combustion, and the outlet end is connected with high pressure grey water pump through high pressure grey water pump inlet pipe.

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